This disclosure relates to a gas turbine engine having a gear train used to drive a fan, and more particularly, the disclosure relates to structure used to support a portion of the gear train relative to a main bearing.
A main bearing is used to rotationally support a compressor rotor and input coupling. In a turbine engine having a gear train, which is used to drive a fan, the same main bearing may be used to rotationally support a gear train component. The gear train component is “soft mounted” to enable the gear train to deflect relative to the main bearing during engine operation. This deflection minimizes gear and bearing stresses by reducing the overall forces exerted within the fan drive system.
In one example arrangement, a main bearing support extends from the main bearing to the engine case. The “soft mount” is provided by a separate flexible structure that includes a steel outer disc that is bolted to the main support where it attaches to the engine case, providing a joint with three flanges. In one example, the main bearing support is constructed from titanium. The flexible support is provided by a stamped steel plate that is welded to a steel inner disc and the outer disc. A torque frame of the gear train is bolted to the inner disc plate.